We use linked individual-level data on school enrollment, physician services received, and prescription medications to measure the effect of the COVID-19 pandemic and associated disruptions on mental health treatment received by adolescents in British Columbia. We also investigate whether these effects are mediated by socioeconomic status and schooling mode. The results suggest substantial increases for non-Indigenous English home language girls in treatment for depression/anxiety, ADHD, eating disorders and other mental health conditions. Indigenous and non-English home language girls also show increases in treatment for depression/anxiety, and Indigenous girls show increases in treatment for ADHD. In contrast, boys show no change or even reductions in treatment for most mental health conditions. These effects vary somewhat by socioeconomic status, but we find no evidence that they vary substantially by schooling mode.